CN105848951B

CN105848951B - In-wheel motor drive unit

Info

Publication number: CN105848951B
Application number: CN201480071288.XA
Authority: CN
Inventors: 黑田优; 铃木健; 铃木健一; 内山尚行
Original assignee: NTN Corp
Current assignee: NTN Corp
Priority date: 2014-01-08
Filing date: 2014-12-19
Publication date: 2019-04-19
Anticipated expiration: 2034-12-19
Also published as: US20170001513A1; US9914349B2; WO2015104980A1; EP3093175A4; EP3093175B1; EP3093175A1; CN105848951A

Abstract

In-wheel motor drive unit (21) has the shell (22) of holding motor part (A), reduction part (B) and wheel bearing portion (C), and motor part (A) includes the stator (23a) for being fixed on shell (22)；The motor rotation axis (24) of shell (22) is rotatably freely supported on via rolling bearing (36,36)；And it is installed on the rotor (23b) of motor rotation axis (24), rolling bearing (36) is set as 8 μm~25 μm to the inner radial gap (δ) before motor part (A) assembling.Motor rotation axis (24) is rotatably freely supported on shell (22) via multiple rolling bearings (36a ', 36b '), and matching between motor rotation axis (24) and the rolling bearing (36a ', 36b ') for supporting the motor rotation axis (24) is combined into transition fit or interference fit.

Description

In-wheel motor drive unit

Technical field

The present invention relates to a kind of in-wheel motor drive units.

Background technique

Previous in-wheel motor drive unit for example has in following patent documents 1, patent document 2 recorded.Wheel Built-in motor driving device is other than needing for device to be integrally contained in the inside of wheel, since its weight, size are to vehicle Nonspring carried mass (driving performance), guest room space size impact, it is therefore desirable to make as much as possible device entirety light weight, Miniaturization.Therefore, patent document 1, patent document 2 in-wheel motor drive unit in, pass through generate driving force electricity Setting makes the rotation of motor part slow down and pass to wheel bearing portion between motivation portion, the wheel bearing portion connecting with wheel The reduction part passed, to seek the miniaturization of motor part and device entirety.Above-mentioned motor part, wheel bearing portion And reduction part is held in shell, shell is installed on vehicle body through not shown draft hitch (suspension).

In addition, in order to promote light weight, miniaturization, and being obtained in wheel in above-mentioned in-wheel motor drive unit The significantly torque needed for bearing portion, motor part is using low torque and high-speed rotation type (such as 15000min^-1Left and right) Motor, and reduction part uses cycloidal reducer small-sized and that high reduction ratio can be obtained.

Motor part uses radial clearance motor, which has: being fixed on the stator of shell, fixed The electricity that the inside of son is equipped with rotor and rotates integrally with rotor across the rotor arranged opposite of gap radially and periphery Motivation rotary shaft.Motor rotation axis is formed as hollow structure, is rotatably freely supported on shell by rolling bearing.

The reduction part for applying cycloidal reducer specifically includes that the reducer input shaft with a pair of of eccentric part, is configured at A pair of of curve ruler of eccentric part, the multiple peripheral snap structures for engaging with the outer peripheral surface of curve ruler and curve ruler being made to generate spinning motion Part and the spinning motion of curve ruler is transmitted to reducer output shaft multiple domestic.Above-mentioned motor rotation axis passes through Spline links in which can transmit torque with reducer input shaft.

Citation

Patent document

Patent document 1: Japanese Unexamined Patent Publication 2012-148725 bulletin

Patent document 2: Japanese Unexamined Patent Publication 2013-148198 bulletin

Summary of the invention

Subject to be solved by the invention

However, in-wheel motor drive unit is accommodated in the inside of car wheel cover, becomes non-spring and carry load, it is therefore necessary to is small-sized Lightweight.However, the output torque of motor is proportional to the volume of motor, if therefore being intended to generate vehicle by motor monomer Driving needed for torque, then need large-scale motor, weight increases.Therefore, by combining retarder with motor It is possible to realize the miniaturizations of motor.If being necessarily required to high speed rotation to increase reduction ratio using small-sized motor, For example, in the case where the retarder for the use of reduction ratio being 11, it is desirable that 15000min-¹The high speed rotation of left and right.

The speed of vehicle (motor vehicle) of in-wheel motor drive unit is equipped with more than from 0km/h to 100km/h The range of high-speed region.Therefore, resonant frequency R and n times forced vibration ingredient, (the n+ α) on draft hitch periphery are secondary strong Compel vibration component intersect point S, S ' (referring to Fig.1 5), exist generate audible area vibration and internal car noise, to occupant with A possibility that carrying out sense of discomfort.Therefore, in order to which (NVH is special for the silence that improves the vehicle for being equipped with in-wheel motor drive unit Property), the forced vibration ingredient to turn around for inhibiting to become the cause of whole vibrations is extremely important.However, in previous wheel In motor drive, for not ground sufficiently using the forced vibration ingredient to turn around as the Retraining Measures of the vibration of representative Study carefully, there are room for improvement.

In addition, also requiring the durability of raising in-wheel motor drive unit, its reliability is improved.

In view of above-mentioned actual conditions, the purpose of the present invention is to provide a kind of small-sized, light weight and silences and durable The excellent in-wheel motor drive unit of property.

Means for solving the problems

To achieve the goals above, it is conceived in in-wheel motor drive unit, especially motor part is repeated Further investigation, as a result, it has been found that following content, first invention is based on the following contents.

In in-wheel motor drive unit, the forced vibration ingredient to turn around is as the motor for being equipped with rotor revolves The rotation of shaft (hereinafter, also referred to as motor rotor) and the vibration generated, and be every revolution generate primary vibration at Point.It is therefore contemplated that the rolling bearing supports motor rotor by being proper range by the running clearance management of rolling bearing To rotate freely, it is able to suppress the rotation with motor rotor and the vibration that generates, is furthermore ensuring the durable of rolling bearing It is also effective in terms of service life and then the endurance life for ensuring motor part.

Here, by making rolling bearing to transport the state of several μm or so of its running clearance management of negative clearance Turn, can be improved its acoustical behavior (yield for inhibiting abnormal sound, vibration), in addition, it is advantageously ensured that its endurance life.However, In in-wheel motor drive unit driving, motor rotor high speed rotation as described above is based on this relationship, supports electric The temperature rise of the rolling bearing of the rotation of machine rotor, the temperature difference constituted between the Internal and external cycle of the rolling bearing are expected with Shangdi Increase, it is known that be easy to make the running clearance of rolling bearing substantially to reduce due to these temperature factors.If running clearance substantially Reduce, in the state that the degree of negative clearance becomes larger persistently using rolling bearing, then rolling bearing is sintered too early, motor part and In-wheel motor drive unit cannot prematurely use.

Therefore, further investigation is repeated in present inventor, as a result, finding the rolling of supports electric machine rotor Bearing is assembled in motor part in such a way that running clearance is as several μm or so of positive gap, can be achieved at the same time rolling bearing, And the silence of in-wheel motor drive unit improves the raising of the inhibition of vibration (abnormal sound) and endurance life, it moreover has been found that In order to ensure the running clearance of above range, the inner radial gap before need to only assembling to motor part is set as 8 μm~25 μ M.

That is, first invention is related to a kind of in-wheel motor drive unit as technological means for achieving the above object, It, which has, keeps motor part, reduction part and the shell in wheel bearing portion, and motor part, which includes, is fixed on shell Stator；The motor rotation axis of shell is rotatably freely supported on via rolling bearing；And it is installed on the motor rotation axis On rotor, reduction part includes the reducer input shaft rotated by motor rotation axis by driving；And it will be after deceleration The reducer output shaft that the rotation of reducer input shaft is transmitted to wheel bearing portion, the spy of the in-wheel motor drive unit Sign is that the inner radial gap before the assembling of rolling bearing is 8 μm~25 μm.

As described above, if before the assembling of the rolling bearing of supporting motor rotary shaft (to motor part assembling before) diameter Internally gap is 8 μm or more, even if the temperature rise (thermal expansion amount of each component when operating) when then operating, the axis of rolling The running clearance held will not become negative clearance, and running clearance be positive gap always, therefore can ensure the desired durable longevity Life.In addition, if assembling before inner radial gap be 25 μm hereinafter, if can prevent running clearance from excessively increasing, will be between operating Gap is maintained in proper range.Therefore, in addition to can effectively inhibit runout with motor rotor and caused by turn around Forced vibration ingredient generation, additionally it is possible to inhibit the amount of movement in the axial direction of motor rotor, prevented as much as possible with electricity The axial movement of motivation rotor and caused by abnormal sound, vibration generation.Therefore, according to first invention, by ensuring supports electric The durability of the rolling bearing of machine rotary shaft, the runout for preventing motor rotation axis etc., can be realized durability and silence Excellent in-wheel motor drive unit.

If being applied with the precompressed in axial direction on above-mentioned rolling bearing, between capable of being operated according to precompressed amount and easily Gap maintains in the appropriate range, therefore the runout etc. because of motor rotation axis (motor rotor) can more efficiently be inhibited to lead The generation of the vibration of cause.In addition, motor rotation axis drives reducer input shaft and makes its rotation (motor rotation axis and deceleration Device input shaft is linked in a manner of it can transmit torque by the way that spline is chimeric equal), thus when with motor rotation axis rotation and When motor rotation axis generates vibration, also produced in the linking part (spline fitting portion) of motor rotation axis and reducer input shaft The raw vibration formed with the mutual sliding contact of the flank of tooth can if being applied with the precompressed in axial direction on rolling bearing The vibration of the linking part of above-mentioned two axis is prevented as much as possible.

It, can will be above-mentioned if precompressed in axial direction is applied by capableing of the elastic component of flexible deformation in the axial direction Precompressed in axial direction is formed as so-called level pressure precompressed.For level pressure precompressed, such as in motor rotation axis and keep rolling In the case that the material difference of the component of dynamic bearing has differences to the thermal expansion amount of the two, precompressed amount will not change, because This, can reliably maintain the running clearance of rolling bearing in the appropriate range, so it is preferred that.It should be noted that conduct Adoptable elastic component can be enumerated such as helical spring, waveform spring, leaf spring.

As the rolling element for constituting above-mentioned rolling bearing, it is preferred to use ceramic balls.This is because: with metal rolling Pearl is compared, the lighter in weight of ceramic balls, therefore can effectively inhibit the moment of friction (fever generated with high speed rotation Amount) increase, and in terms of seeking the lightweight of rolling bearing and in-wheel motor drive unit advantageously.In addition, By using ceramic balls as rolling element, rolled hence for used in this electrical equipment of in-wheel motor drive unit As problem because the patience of type of impairment caused by magnetic field is improved in dynamic bearing.

In addition, as the retainer for constituting above-mentioned rolling bearing, it is preferred to use the retainer of resin.Thereby, it is possible to Make rolling bearing and the further lightweight of in-wheel motor drive unit.

It, can be right including above-mentioned rolling bearing if being provided with the lubricating structure to motor part supply lubricating oil Each position of motor part is suitably lubricated, cools down.

In above structure, reduction part can be had: reducer input shaft using such as flowering structure；Rotatably freely protect It is held in the revolution component of the eccentric part of the reducer input shaft, the revolution component is with the rotation of reducer input shaft and to subtract Revolution motion is carried out centered on the axis of rotation of fast device input shaft；Engage with the peripheral part of the revolution component and makes component production of revolving The peripheral snap component of raw spinning motion；And the spinning motion for the component that revolves is converted into the rotary shaft with reducer input shaft Rotary motion centered on the heart and the movement conversion mechanism transmitted to reducer output shaft.

In addition, being ground from motor rotation axis of the various viewpoints to the rotor for being equipped with in-wheel motor drive unit Study carefully, it was found that following content, the second invention are based on following content.

(1) vibration analysis

The motor rotation axis of rotor is installed (hereinafter, also referred to as motor rotor.) the forced vibration turned around at Point it is the rotation with motor rotor and the vibration generated, and is that every revolution generates primary vibration component.If being in The centroid and the inconsistent state in the center of inertia of motor rotor, then due to passing through the amount of unbalance of motor rotor and turning It counts determining centrifugal force and generates the vibration, the amount of unbalance that reduces to the minimum is the effective means for inhibiting vibration.

Even if in addition, the centroid in motor rotor is consistent with the center of inertia, and strongly inhibiting amount of unbalance Motor rotor in, also there are the feelings in gap between motor rotation axis and the rolling bearing for supporting the motor rotation axis An important factor under condition, runout occurs for motor rotor, can become vibration.Moreover, in the biggish feelings of weight of motor rotor Under condition, runout influences to further increase caused by vibration.

In particular, it is known in the in-wheel motor drive unit for becoming nonspring carried mass, in the weight of motor rotor In biggish situation, the fit clearance between motor rotation axis and rolling bearing is affected caused by vibration, vibrates quick Sense, and it is difficult to realize the decaying of vibration beyond expection.Also, known inhibition runout can largely facilitate to carry The silence of the vehicle of in-wheel motor drive unit.

(2) cooperation between motor rotation axis and rolling bearing

In order to inhibit runout, it is conceived to the fit clearance eliminated between motor rotation axis and rolling bearing, it is known that will be electric It is effective that cooperation between motivation rotary shaft and rolling bearing, which is set as transition fit or interference fit,.Interference fit refers to electronic The diameter of axle of machine rotary shaft relationship bigger than the internal diameter of rolling bearing always, clearance fit refer to motor rotation axis in contrast Diameter of axle relationship smaller than the internal diameter of rolling bearing always.Transition fit, which refers to, is likely to be at clearance fit appointing into interference fit A kind of cooperation.Here, for transition fit, 21 μm~2 μm of magnitude of interference is set as relative to the tolerance of transverse bearing as axis, For interference fit, it is set as relative to the tolerance of transverse bearing 45 μm~22 μm of magnitude of interference as axis, for clearance fit, makees 0 μm~43 μm of gap is set as relative to the tolerance of transverse bearing for axis.

(3) cooperation between shell and rolling bearing

Even if the fit clearance of motor rotation axis and roller bearing shop is eliminated, between existing between rolling bearing and shell In the case where gap, runout can still occur for motor rotation axis.In the case where considering the assembling of bearing, by the inner ring of bearing and Outer ring both sides are set as being interference fitted, assembling when bearing rolling element can damage orbital plane, be unfavorable for bearing service life and Vibration.Therefore, in the case where transition fit or interference fit will be set as between motor rotation axis and bearing inner race, preferred axis It is clearance fit between bearing outer-ring and shell.In this case, it is known that need to inhibit the countermeasure of runout.

(4) Bearing inner gap

There are Bearing inner gaps in rolling bearing.Bearing inner gap since the temperature difference of Internal and external cycle is usually smaller, From the viewpoint of bearing life, it is more slightly larger than primary clearance to be chosen to be running clearance.However, the Bearing inner gap becomes electronic One of runout key factor of machine rotor.In the in-wheel motor drive unit for becoming nonspring carried mass, it is known that also to the vibration Pendulum produces bigger effect.

(5) the spline fitting portion between motor rotation axis and reducer input shaft

In order to transmit torque, motor rotation axis links with reducer input shaft by the way that spline is chimeric, it is known that inhibits because of electricity The movements such as the straight line registration error that is generated between motivation rotary shaft and reducer input shaft, the vibration for playing tooth generation when engaging It is effective.

As technological means for achieving the above object, the second invention is related to a kind of in-wheel motor drive unit, Have motor part, reduction part, wheel bearing portion and shell, the motor part includes: to be fixed on determining for the shell Son；The motor rotation axis of the shell is rotatably freely supported on via multiple rolling bearings；And it is installed on the motor Rotor in rotary shaft, the motor rotation axis of the motor part drive the reducer input shaft of the reduction part to rotate, make The rotation of the reducer input shaft is slowed down and is transmitted to reducer output shaft, and the wheel bearing portion and the retarder export Axis connection, the in-wheel motor drive unit are characterized in that the motor rotation axis is revolved via multiple rolling bearings Turn to be supported on the shell freely, between the motor rotation axis and the rolling bearing of the bearing motor rotation axis With being combined into transition fit or interference fit.According to the mechanism, following in-wheel motor drive unit can be realized, will turn one The forced vibration ingredient of circle be suppressed to can using low torque and the degree of the motor of high-speed rotation type, and realize it is small-sized, Light weight, silence is excellent, and improves durability.

It is preferred that matching between above-mentioned rolling bearing and shell is combined into clearance fit.The rolling bearing in assembling as a result, Rolling element will not damage orbital plane, can be avoided the lost of life of bearing.

It is preferred that the level pressure precompressed being applied on above-mentioned rolling bearing in axial direction.Thereby, it is possible to eliminate between Bearing inner Gap inhibits a factor of the runout of motor rotation axis.In the case where level pressure precompressed, it is not easily susceptible to generate because of thermal expansion difference Axial displacement variation influence, therefore be able to suppress the variation of precompressed, be suitable for in-wheel motor drive unit.

Preferably, double base is carried out via a pair of of rolling bearing and to above-mentioned motor rotation axis, the rolling bearing Either one is by being fixed the side for the pressing member for being fixed on shell and abutting with the end face of bearing outer ring.Rolling bearing with Matching between shell is combined into clearance fit, but since the end face of bearing outer ring is pressed, is able to suppress motor rotation axis The straight line registration error that is generated between reducer input shaft, because vibration for playing tooth formation of spline fitting portion engaged etc. it is dynamic Make.

By will be by the fixed rolling bearing of above-mentioned pressing member as the reduction part side of supporting motor rotary shaft The bearing in portion misses so as to effectively inhibit the straight line registration generated between motor rotation axis and reducer input shaft The movement of the vibration for playing tooth formation of engagement poor, because of spline fitting portion etc..

By above-mentioned pressing member be hollow plectane, so as to by change plectane plate thickness easily vary by Pressure, additionally it is possible to easily cope with the shape change of press section.

Above-mentioned press is constituted by the base portion using hollow plectane and from the base portion to the prominent multiple abutting parts in internal diameter side Component is pressed, so that the trackability of multiple protruding portion to cycle surface is good in addition to the advantages of above-mentioned plectane is brought, is applied steady Fixed pressing force.

It is preferred that the plate thickness of above-mentioned pressing member is 0.5mm~5mm.In the case where plate thickness is 0.5mm situation below, pressing force Smaller, the retentivity of bearing becomes smaller, so not preferably, on the other hand, in the case where plate thickness is 5mm or more, cannot achieve pair In the shortening that the structural requirement of in-wheel motor drive unit is axial direction, so not preferably.

Invention effect

More than, according to first invention and the second invention, it can be realized light weight, small-sized and silence and durability Excellent in-wheel motor drive unit.

Detailed description of the invention

Fig. 1 is the figure for showing the in-wheel motor drive unit of an embodiment of first invention.

Fig. 2 is the O-O line regarding sectional view of Fig. 1.

Fig. 3 is the explanatory diagram for showing the load for the curve ruler for acting on Fig. 1.

Fig. 4 is the sectional elevation of the rotary pump of Fig. 1.

Fig. 5 is the schematic cross sectional view of the rolling bearing of supporting motor rotary shaft.

Fig. 6 is the longitudinal section view of waveform spring.

Fig. 7 is the figure for showing the in-wheel motor drive unit of an embodiment of the second invention.

Fig. 8 is the sectional elevation at the O-O of Fig. 7.

Fig. 9 is the explanatory diagram for showing the load for the curve ruler for acting on Fig. 7.

Figure 10 is the sectional elevation of the rotary pump of Fig. 7.

Figure 11 a is by the amplified partial, longitudinal cross-sectional of reduction part side section of motor rotation axis.

Figure 11 b is at the P-P line of Figure 11 a to the main view of pressing member when view observation.

Figure 12 is the amplified longitudinal section view of motor rotation axis that will be equipped with rotor.

Figure 13 is the longitudinal section view of waveform spring.

Figure 14 is the main view for showing the variation of pressing member.

Figure 15 is the explanatory diagram for showing the relationship of resonant frequency and forced vibration ingredient.

Figure 16 is the schematic top view of electric motor vehicle.

Figure 17 be observe from the rear the electric motor vehicle of Figure 16 when schematic cross sectional view.

Specific embodiment

It is said according to summary of the Figure 16 and Figure 17 to the electric motor vehicle 11 for being equipped with in-wheel motor drive unit It is bright.As shown in figure 16, electric motor vehicle 11 has: chassis 12, a pair of of the front-wheel 13 functioned as deflecting roller, as drive The in-wheel motor drive unit 21 of driving wheel and a pair of rear wheels 14 functioned and the rear-wheel 14 for respectively driving left and right.Such as Shown in Figure 17, rear-wheel 14 is contained in the inside of the car wheel cover 12a on chassis 12, is fixed on bottom via draft hitch (suspension) 12b The lower part of disk 12.

The suspension link supporting wheels 14 that draft hitch 12b is extended through left and right, and by including helical spring and damping The supporting member of device absorbs the vibration that rear-wheel 14 is subject to from ground to inhibit the vibration on chassis 12.Also, the suspension link in left and right Linking portion be provided with inhibit turning when etc. vehicle body inclined stabilizer.The concave-convex of road surface is servo-actuated in order to improve Property, the driving force of rear-wheel 14 is efficiently transmitted to road surface, draft hitch 12b preferably use can make the wheel of left and right independently The independent suspension formula of up and down motion.

In the electric motor vehicle 11, the rear-wheel 14 for respectively driving and controlling is internally provided in the car wheel cover 12a controlled And the in-wheel motor drive unit 21 for rotating them, without motor, drive shaft and difference are arranged on chassis 12 Moving gear mechanism etc..Therefore, has the rear-wheel 14 that guest room space can be ensured to be to larger and left and right can be controlled respectively The advantages of rotation.

In order to improve the riding stability and NVH characteristic of electric motor vehicle 11, need to inhibit nonspring carried mass.In addition, In order to expand the guest room space of electric motor vehicle 11, it is desirable that minimize in-wheel motor drive unit 21.Therefore, such as Fig. 1 institute Show, using the in-wheel motor drive unit 21 of first invention and the embodiment of the second invention.

It is illustrated according to in-wheel motor drive unit 21 of the FIG. 1 to FIG. 6 to an embodiment of first invention.Right Before the feature structure of the in-wheel motor drive unit of present embodiment is illustrated, overall structure is illustrated.Such as Fig. 1 Shown, in-wheel motor drive unit 21 has: generate the motor part A of driving force, make motor part A rotation slow down and it is defeated The reduction part B out and wheel bearing portion C for transmitting the output from reduction part B to rear-wheel 14, they are held in shell 22.In addition, detailed content is aftermentioned, which has to each portion of motor part A and reduction part B The lubricating structure of position supply lubricating oil.Motor part A and reduction part B is installed on electrical motor-driven in the state of being accommodated in shell 22 In the car wheel cover 12a (referring to Fig.1 7) of vehicle 11.The shell 22 of present embodiment by bolt by store motor part A part with The part fastening of storage reduction part B is combined into, if removing bolt, two parts can divide (separation).This specification with And in technical solution, shell 22 refers to the casing part of storage motor part A and stores this both sides of the casing part of reduction part B.

Motor part A is radial clearance motor, comprising: is fixed on the stator 23a of shell 22, in the inside of stator 23a It is revolved across the rotor 23b arranged opposite of gap radially and hollow structure and by the rotor 23b motor for being installed on periphery Shaft 24.

Motor rotation axis 24 is by being respectively configured axially side (right side of Fig. 1 is also referred to as " inner disc side " below) And the end of the other side (left side of Fig. 1 is also referred to as " external disk side " below) rolling bearing 36,36 and be supported to relative to Shell 22 rotates freely.Rolling bearing 36 is so-called deep groove ball bearing, and Sketch as shown in Figure 5 is such, is had: chimeric It is fixed on the outer ring 36a of the aperture surface of shell 22 (strictly speaking the rolling bearing 36 of inner disc side is cover 71)；It is fitted and fixed in electricity The inner ring 36b of the outer diameter face of motivation rotary shaft 24；Configure multiple ball 36c between outer ring 36a and inner ring 36b；And it will Multiple ball 36c remain the retainer (not shown) of the state separated in the circumferential.

Motor rotation axis 24 is constituted such as the case-hardened steel by SCM415, SCM420, is had and is quenched by implementing carburizing The hardened layer of fire tempering and formation.The detailed illustration is omitted, hardened layer be formed in it is in motor rotation axis 24, at least for rotor The position that is fitted and fixed with inner ring 36b of 23b, rolling bearing 36.It is prevented as much as possible as a result, with rotor 23b, rolling bearing 36 Assembling and deformation, abrasion, the damage of motor rotation axis 24 etc. that generate.It should be noted that in motor rotation axis 24 , the hardness of the part for being formed with hardened layer be HRC62~66.5 or so, the hardness of core is HRC29~38 or so.In this way, The core of motor rotation axis 24 has toughness, therefore deformation when being resistant to high speed rotation.

Reduction part B is included by motor rotation axis 24 drives and rotates reducer input shaft 25 and is kept retarder defeated Enter the reducer output shaft 28 transmitted after the rotation deceleration of axis 25 to wheel bearing portion C.The axial direction of reducer input shaft 25 is big The end of central portion and external disk side is caused to be scrolled bearing 37a, 37b bearing respectively to rotate certainly relative to reducer output shaft 28 Such as.Reducer input shaft 25 has eccentric part 25a, 25b.For the centrifugal force generated by eccentric motion of cancelling out each other, two partially Center portion 25a, 25b is arranged in a manner of making 180 ° of phase deviation.

Motor rotation axis 24 and reducer input shaft 25 pass through spline (including sawtooth.It is same as below.) be fitted into and link, The driving force of motor part A is transmitted to reduction part B.Linking part (the spline of motor rotation axis 24 and reducer input shaft 25 Fitting portion) it is configured to, even if reducer input shaft 25 tilts to a certain extent, also inhibit the influence to motor rotation axis 24.

Reduction part B is also equipped with: as curve ruler 26a, 26b of revolution component, it is defeated to be rotatably freely held in retarder Enter eccentric part 25a, 25b of axis 25；Peripheral part as multiple export trades 27 of peripheral snap component, with curve ruler 26a, 26b Engaging；The spinning motion of curve ruler 26a, 26b are converted to the rotary motion of reducer output shaft 28 by movement conversion mechanism； And balance weight 29,29, it is configured adjacently in the axially external of eccentric part 25a, 25b.

Reducer output shaft 28 has flange part 28a and axle portion 28b.In the end face of flange part 28a, exported with retarder Fixed domestic 31 hole is alternately formed on circumference centered on the axis of rotation of axis 28 etc..In addition, axle portion 28b passes through spline The chimeric wheel hub 32 for being linked to wheel bearing portion C transmits the output of reduction part B to wheel 14 (Figure 16,17 references).

As shown in Fig. 2, curve ruler 26a is multiple with being made of trochoids system curves such as the outer trochoids of circle in its peripheral part Waveform.In addition, curve ruler 26a has through hole 30a, 30b in the axial direction that its both ends of the surface is open.Through hole 30a is with song Be equally spaced on circumference centered on the rotation axle center of line plate 26a it is multiple, and each through hole 30a accommodate one it is aftermentioned Domestic 31.Through hole 30b is set to the center of curve ruler 26a, and chimeric with the eccentric part 25a of reducer input shaft 25.

Curve ruler 26a is supported to rotate freely relative to eccentric part 25a by rolling bearing 41.Rolling bearing 41 is Cylinder roller bearing has: having inner track face 42a and the inner ring 42 chimeric with the outer diameter face of eccentric part 25a in outer diameter face； It is formed directly into the outer side track face 43 of the aperture surface of the through hole 30b of curve ruler 26a；Configuration is in inner track face 42a and outside Multiple cylindrical rollers 44 between siding track face 43；And keep the retainer (not shown) of cylindrical roller 44.Inner ring 42 has From the axial ends portion of inner track face 42a to radial outside flange part 42b outstanding.In the rolling bearing 41 of present embodiment In, it is formed with inner track face 42a on the inner ring 42 being arranged independently of eccentric part 25a, but can also be directly in eccentric part Inner track face is formed in the outer diameter face of 25a to omit inner ring 42.The detailed illustration is omitted and explanation, curve ruler 26b tool There is structure identical with curve ruler 26a, passes through the axis of rolling with structure identical with the rolling bearing 41 of bearing curve plate 26a It holds and is supported to rotate freely relative to eccentric part 25b.

As shown in Fig. 2, export trade 27 is equally spaced set on the circumference centered on the axis of rotation of reducer input shaft 25 It sets.When curve ruler 26a, 26b revolution motion, it is formed in the waveform of the curve shape of the peripheral part of curve ruler 26a, 26b and outer Pin 27 engages in the circumferential, so that curve ruler 26a, 26b be made to generate spinning motion.As shown in Figure 1, each export trade 27 exists via configuration The rolling bearing (needle bearing) 61 of the end of its inner disc side and external disk side and needle bearing 61 is maintained at the outer of inner circumferential Pin covers 60 and is rotatably freely supported on shell 22.According to this structure, the contact resistance between export trade 27 and curve ruler 26a, 26b Reduce.

The detailed illustration is omitted, and export trade cover 60 is by the rotation preventive mechanism (not shown) with elastic bearing function with floating type State is supported on shell 22.The reason is that absorbing the biggish radial load of the generations such as the turning of vehicle, anxious acceleration-deceleration, power Square load prevents the spinning motion by curve ruler 26a, 26b to be converted to the movement conversion of the rotary motion of reducer output shaft 28 The breakage of the component parts (curve ruler 26a, 26b, export trade 27 etc.) of mechanism.

Balance weight 29 is in generally fan-shaped shape, has the through hole chimeric with reducer input shaft 25, in order to eliminate because of curve The rotation of plate 26a, 26b and the unbalance inertia force that generates is even, the position adjacent with each eccentric part 25a, 25b and partially in the axial direction Center portion 25a, 25b configures with changing 180 ° of phases.

As shown in Figure 1, movement conversion mechanism includes: to be held in multiple domestic the 31 of reducer output shaft 28 and be set to song The through hole 30a of line plate 26a, 26b.As shown in Fig. 2, domestic 31 in the circle centered on the axis of rotation of reducer output shaft 28 It is equally spaced on week, reducer output shaft 28 is fixed in the end of external disk side.Reducer output shaft 28 and retarder are defeated Enter the configuration of axis 25 on the same axis, therefore the spinning motion of curve ruler 26a, 26b are converted to the rotation of reducer input shaft 25 Rotary motion centered on axle center is simultaneously transmitted to reducer output shaft 28.In addition, in order to reduce the friction with curve ruler 26a, 26b Resistance is provided with needle bearing 31a in the inner circumferential of the through hole 30a of curve ruler 26a, 26b.

Stabilizer 31b is provided on reduction part B.Stabilizer 31b includes the annular portion 31c of annulus shape and from annulus The cylindrical portion 31d that the aperture surface of portion 31c axially extends, annular portion 31c is fixed in the end of each domestic 31 inner disc side.By This, domestic 31 load applied from curve ruler 26a, 26b to a part are supported via stabilizer 31b by all domestic 31, Therefore can reduce act on domestic 31 stress, to improve durability.

As shown in Fig. 2, through hole 30a setting with multiple domestic 31 corresponding positions, the internal diameter ruler of through hole 30a The very little outer diameter being set as than domestic 31 (refers to " maximum outside diameter including needle bearing 31a ".It is same as below.) ruler is provided greatly It is very little.

The state for the load for acting on curve ruler 26a, 26b when here, driving according to Fig. 3 to motor part A is illustrated.

It is set to the axle center O of the eccentric part 25a of reducer input shaft 25₂It is eccentric from the axle center O of reducer input shaft 25 Eccentric amount e.Curve ruler 26a is installed in the periphery of eccentric part 25a, eccentric part 25a rotatably supports curve ruler 26a, Therefore axle center O₂It also is the axle center of curve ruler 26a.The peripheral part of curve ruler 26a is formed by wavy curve, in the circumferential at equal intervals Ground has the recess portion 34 being recessed radially.Around curve ruler 26a, it is equipped in the circumferential centered on the O of axle center multiple The export trade 27 engaged with recess portion 34.

In Fig. 3, when reducer input shaft 25 rotates counterclockwise on paper, eccentric part 25a is carried out with axis Revolution motion centered on heart O, therefore the recess portion 34 of curve ruler 26a is circumferentially successively abutted with export trade 27.As a result, curve Plate 26a is from multiple export trades 27 by the load Fi shown in arrow in figure, along clockwise direction rotation.

In addition, with axle center O on curve ruler 26a₂Centered on and be equipped with multiple through hole 30a in the circumferential.With deceleration Domestic the 31 of the combination of device output shaft 28 pass through each through hole 30a, which coaxially configures with axle center O.Perforation The big predetermined size of outer diameter of the internal diameter of hole 30a than domestic 31, therefore domestic 31 will not be as the barrier of the revolution motion of curve ruler 26a Hinder, domestic 31 extract the spinning motion of curve ruler 26a and rotate reducer output shaft 28.At this point, with reducer input shaft 25 It compares, reducer output shaft 28 becomes high torque (HT) and slow speed, and curve ruler 26a is carried as illustrated in the drawing from multiple domestic 31 Lotus Fj.The resultant force Fs of above-mentioned multiple load Fi, Fj is applied to reducer input shaft 25.

The direction of resultant force Fs is according to geometric conditions, centrifugal force such as the waveform shape of curve ruler 26a, the quantity of recess portion 34 Influence and change.Specifically, with connection rotation axle center O₂At right angle and pass through rotation axle center O with the straight line Y of axle center O₂Base Directrix X and resultant force Fs angulation_αSubstantially changed in 30 °~60 °.Above-mentioned multiple load Fi, Fj are inputted in retarder During axis 25 turns around, the direction of load, size change, as a result, acting on the resultant force of reducer input shaft 25 The direction of the load of Fs, size also change.Also, when reducer input shaft 25 turns around, the waveform of curve ruler 26a Recess portion 34 is decelerated one spacing of rotation clockwise, becomes the state of Fig. 3, repeats above situation.

As shown in Figure 1, wheel bearing portion C has the wheel hub 32 linked with reducer output shaft 28 and by wheel hub 32 Bearing is the wheel bearing 33 rotated freely relative to shell 22.Wheel hub 32 has cylindric hollow portion 32a and flange part 32b.Rear-wheel 14 (referring to Fig.1 6,17) are fixedly connected with by bolt 32c on flange part 32b.The axis of reducer output shaft 28 Portion 28b links with the hollow portion 32a of wheel hub 32 by the way that spline is chimeric, and the output of reducer output shaft 28 is transferred to wheel as a result, Hub 32.

Wheel bearing 33 is multiple row angular contact ball bearing, and is had: inner member, has and is formed directly into wheel hub 32 Outer diameter face inner track face 33f and the inner ring 33a chimeric with the path stage portion of outer diameter face；Outer ring 33b is fitted into solid Due to the aperture surface of shell 22；Multiple rolling element (ball) 33c, they are configured between inner member and outer ring 33b；Retainer Ball 33c is remained the state separated on week by 33d；And containment member 33e, to the axial direction of wheel bearing 33 Both ends are sealed.

Next, being illustrated to lubricating structure.Lubricating structure is to each portion of cooling motor part A and reduction part B Position supply lubricating oil.As shown in Figure 1, the lubricating structure specifically include that be set to the lubricant passage way 24a of motor rotation axis 24 with And oil port 24b；Be set to reducer input shaft 25 lubricant passage way 25c and oil port 25d, 25e, 25f；It is set to the lubricant passage way 31e of stabilizer 31b；It is set to domestic 31 lubricant passage way 31f；It is set to the lubrication of shell 22 Oily outlet 22b, lubricating oil accumulating part 22d, lubricant passage way 22e and lubricant passage way 45 (45a~45c)；And rotary pump 51.? The flow direction of the expression lubricating oil of hollow arrow shown in Fig. 1.

Lubricant passage way 24a motor rotation axis 24 axially inside extension, on the inside edge of reducer input shaft 25 Axially extending lubricant passage way 25c is connect with lubricant passage way 24a.Oil port 25d, 25e are from lubricant passage way 25c direction The outer diameter face of reducer input shaft 25 radially extends, and oil port 25f is from lubricant passage way 25c towards reducer input shaft 25 outer end face axially extends.

Lubricating oil inside reduction part B is discharged the lubricating oil outlet 22b for being set to shell 22, is arranged in reduction part B Position at shell 22 at least one position.The lubricant passage way 24a of lubricating oil outlet 22b and motor rotation axis 24 is passed through It is connected by lubricating oil accumulating part 22d, lubricant passage way 22e and lubricant passage way 45.Therefore, it is discharged from lubricating oil outlet 22b Lubricating oil via lubricant passage way 22e, circulating oil path 45 etc. and to the lubricant passage way 24a of motor rotation axis 24 flow back.It needs Illustrate, lubricating oil accumulating part 22d between lubricating oil outlet 22b and circulating oil path 22e is set has and temporarily stockpile The function of lubricating oil.

As shown in Figure 1, the circulating oil path 45 for being set to shell 22 includes: the axis axially extended in the inside of shell 22 To oil circuit 45a；The radial oil circuit 45c for connecting and radially extending with the end of the inner disc side of axial oil circuit 45a；And and axis The radial oil circuit 45b for connecting and radially extending to the end of the external disk side of oil circuit 45a.Radial oil circuit 45b will be from rotary pump Oil circuit 45a is supplied the lubricating oil of 51 force feeds in the axial direction, is supplied to the lubricating oil of axial oil circuit 45a via radial oil circuit 45c to electricity The lubricant passage way 25c supply of the lubricant passage way 24a and reducer input shaft 25 of motivation rotary shaft 24.

The lubricant passage way 22e and circulating oil path 45 connecting with the downstream side of lubricating oil accumulating part 22d is arranged in rotary pump 51 Between, make lubricating oil forced circulation.By the way that the configuration of rotary pump 51 in shell 22, can be prevented from driving as in-wheel motor The whole enlargement of device 21.

As shown in figure 4, rotary pump 51 is Gerotor pump, have: being rotated using the rotation of reducer output shaft 28 Internal rotor 52；The outer rotor 53 of driven rotation is carried out with the rotation of internal rotor 52；Sky between two rotors 52,53 is set Between pump chamber 54；The suction inlet 55 being connected to lubricant passage way 22e；And the row being connected to the radial oil circuit 45b of circulating oil path 45 Outlet 56.

Internal rotor 52 is with rotation center c₁Centered on and rotate, on the other hand, outer rotor 53 is with the rotation with internal rotor 52 Center c₁Different rotation center c₂Centered on and rotate.In this way, internal rotor 52 and outer rotor 53 are respectively in different rotations Heart c₁、c₂Centered on and rotate, therefore the volume of pump chamber 54 continuously changes.The lubrication of pump chamber 54 is flowed into from suction inlet 55 as a result, Oil is from outlet 56 to radial oil circuit 45b force feed.

Lubricating structure mainly have more than structure, by as described below to each of motor part A and reduction part B Position supplies lubricating oil, to be lubricated, cool down to each position of motor part A and reduction part B.

Firstly, the supply of rotor 23b and stator 23a of from the lubricating oil to motor part A are mainly by via shell 22 A part of lubricating oil of lubricant passage way 24a of the supply of circulating oil path 45 to motor rotation axis 24 revolved by with motor The rotation of shaft 24 and the influence of centrifugal force generated ejects progress from oil port 24b.That is, from oil port The lubricating oil of 24b discharge is supplied to rotor 23b, later, supply to stator 23a.In addition, the inner disc of supporting motor rotary shaft 24 The rolling bearing 36 of the end of side mainly by a part of the lubricating oil flowed in circulating oil path 45 from shell 22 with it is electronic It oozes out and is lubricated between machine rotary shaft 24.In addition, the rolling bearing 36 of the end of the external disk side of supporting motor rotary shaft 24 Mainly lubricated by the lubricating oil oozed out between rotary pump 51 and shell 22.

Next, flowing into the lubricant passage way 25c of reducer input shaft 25 via the lubricant passage way 24a of motor rotation axis 24 Lubricating oil by with reducer input shaft 25 rotation generate centrifugal force and pressure influenced from oil port 25d, 25e, 25f are discharged to reduction part B, later, flow as follows.

The lubricating oil being discharged from oil port 25e, 25f supplies defeated to bearing retarder due to the effect of centrifugal force Enter rolling bearing 37a, 37b of axis 25.In addition, the lubricating oil flowed out from oil port 25e is by the profit into stabilizer 31b Lubricating oil road 31e is guided and is reached the lubricant passage way 31f in domestic 31, (is rolled from lubricant passage way 31f to domestic 31 rolling bearing Needle bearing) 31a supply.Further, since centrifugal force, on one side to curve ruler 26a, 26b and domestic 31 abutment portion, curve ruler 26a, 26b and the abutment portion of export trade 27 support the rolling bearing 61 of export trade 27 and support the rolling of reducer output shaft 28 Bearing 46 etc. is lubricated mobile to radial outside on one side.

On the other hand, it supplies from the lubricating oil that oil port 25d is discharged to the axis of rolling of bearing curve plate 26a, 26b Hold 41 (referring to Fig. 2).In addition, in the same manner as the lubricating oil being discharged from oil port 25e, 25f, due to centrifugal force, on one side To curve ruler 26a, 26b with domestic 31 abutment portion, curve ruler 26a, 26b and the abutment portion of export trade 27 etc. be lubricated one While mobile to radial outside.

By the flowing of above such lubricating oil, each position in reduction part B is lubricated.Also, it reaches outer The lubricating oil of the inner wall of shell 22 is discharged from lubricating oil outlet 22b and is accumulated in lubricating oil accumulating part 22d.In this way, due to Lubricating oil accumulating part 22d is provided between lubricating oil outlet 22b and the lubricant passage way 22e for being connected to rotary pump 51, therefore special Even if not being to wait temporarily to generate the lubricating oil not drained by rotary pump 51 when rotating at high speed, the lubricating oil can be also accumulated in Lubricating oil accumulating part 22d.As a result, the increase of the fever at each position of reduction part B, torque loss can be prevented.It is another When aspect, especially low speed rotation etc., the lubricants capacity for reaching lubricating oil outlet 22b is reduced, but in this case, energy The lubricating oil for being accumulated in lubricating oil accumulating part 22d is enough set to be back to lubricant passage way 24a, 25c, therefore can be steadily to motor Portion A and reduction part B supplies lubricating oil.

It should be noted that the lubricating oil inside reduction part B is moved downward because of centrifugal force and gravity.Thus it is preferred to For the in-wheel motor drive unit 21 is located at the side of the lower part of in-wheel motor drive unit 21 with lubricating oil accumulating part 22d Formula is installed on electric motor vehicle 11.

The overall structure of in-wheel motor drive unit 21 as described above, present embodiment in-wheel motor drive unit 21 have feature structure as shown below.

Firstly, being the axis of rolling rotated freely relative to shell 22 by the bearing of motor rotation axis 24 in motor part A It holds in the case that the inner radial gap delta (referring to Fig. 5) of (deep groove ball bearing) 36,36 before assembling is set as 8 μm~25 μm, group Shell 22 loaded on motor part A.In this way, if the inner radial gap delta before the assembling of rolling bearing 36 is 8 μm or more, i.e., Just consider that temperature rise when operating, the running clearance of rolling bearing 36 will not become negative clearance, running clearance is always Positive gap.In addition, if assembling before inner radial gap delta be 25 μm hereinafter, if can prevent running clearance from excessively increasing feelings Condition.Therefore, according to above structure, then the running clearance of rolling bearing 36,36 can be maintained in the range of positive gap Value appropriate, therefore rolling bearing 36 can ensure desired endurance life, and can effectively inhibit with being equipped with The runout of the motor rotation axis 24 of rotor 23b and caused by the generation of forced vibration ingredient turned around.Furthermore it is possible to inhibit Amount of movement in the axial direction of motor rotation axis 24, can prevent as much as possible with the axial movement of motor rotation axis 24 and Caused by abnormal sound, vibration generation.

Here, the inner radial gap delta before assembling is described in detail.The inner radial gap delta refers to, such as Fig. 5 institute Show, it, will be outer in the state of before rolling bearing (deep groove ball bearing) 36 is assembled in motor rotation axis 24 or shell 22 It is fixed to enclose either 36a or inner ring 36b, amount of movement when moving another party in radial directions.In other words, refer to Inner track face and the ball of inner ring 36b are formed in the state of abutting ball 36c with the outer side track face of outer ring 36a Gap between 36c, or it is formed in outer ring 36a's in the state of abutting ball 36c with the inner track face of inner ring 36b Gap between outer side track face and ball 36c.Fig. 5 schematically shows the situation of the latter.

In addition, in the present embodiment, rolling bearing 36,36 is previously applied the load (precompressed) in axial direction.This In the case of, if applying precompressed amount appropriate, it is easy to maintain the running clearance of rolling bearing 36 in the appropriate range, therefore energy The generation of vibration caused by enough more efficiently inhibiting because of runout of motor rotor etc..In addition, motor rotation axis 24 with subtract Fast device input shaft 25 can transmit torque by the chimeric connection of spline, thus when the rotation with motor rotation axis 24 and When motor rotation axis 24 generates vibration, in the linking part (spline fitting portion) of motor rotation axis 24 and reducer input shaft 25 There is also generating with being vibrated caused by mutual sliding contact of the flank of tooth etc., if but being applied to rolling bearing 36,36 Add the precompressed in axial direction, then can prevent the vibration of the linking part of above-mentioned two axis 24,25 as much as possible.

The method for applying precompressed is roughly divided into positioning and sets precompressed and level pressure precompressed.For example, the side mechanically positioned It is owned by France to set precompressed in positioning, the side of elastic component that can be elastically deformed in an axial direction using helical spring, waveform spring, leaf spring etc. It is owned by France in level pressure precompressed.In the case where the material of motor rotation axis 24 is different from the material of shell 22, according to mechanical Then there is the thermal expansion difference because of motor rotation axis 24 and shell 22 in the method that ground is positioned, and make precompressed amount, the i.e. axis of rolling A possibility that 36 running clearance significantlys change is held, not preferably.Therefore, in the present embodiment, using being not easily susceptible to because of heat Differential expansion and the level pressure precompressed of the influence of the variation of axial displacement generated.Level pressure precompressed can be by using above-mentioned this elasticity Component realizes, in the present embodiment, using amplifying the waveform spring 70 shown in Fig. 6.In addition, level pressure precompressed is preferably one As precompressed amount, in the case where the diameter of axle for the motor rotation axis 24 being externally embedded to for the inner ring 36b of rolling bearing 36 is set as d, Precompressed amount is set in the range of 4d~10d (N).

Fig. 6 is the longitudinal section view of waveform spring 70.The waveform spring 70 is formed and leaf spring is wound spiral, Axial central portion, which has, bends to undulatory spring portion 70a, has flat seat surface 70b at axial both ends.Such as Fig. 1 It is shown, by by the waveform spring 70 with compressive state be located in shell 22 (central plug 73) and inner disc side rolling bearing 36 it Between, to apply the precompressed (level pressure precompressed) in axial direction to rolling bearing 36,36.

Here, referring to Fig.1, to the level pressure precompressed in the application axial direction of a pair of of rolling bearing 36,36 for using waveform spring 70 Method be illustrated.The application while assembling that level pressure is pressed in motor part A in advance terminates, therefore, hereinafter, to motor part A The summary of assembling sequence be illustrated.It should be noted that motor part A's is assembled in the shell 22 for making reduction part B and electricity The shell 22 of motivation portion A carries out in the state of separating.

Firstly, stator 23a to be fixed on to the inner circumferential of the shell 22 of the motor part A for the state that cover 71 is removed, then will The rolling bearing 36 of external disk side (being left side in Fig. 1) is assembled in shell 22.Next, rotor 23b and rotation biography will be equipped with The motor rotation axis 24 of the rotor 72a of sensor 72 is inserted into the inner circumferential of shell 22, by the end of the external disk side of motor rotation axis 24 The internal diameter of the inner ring 36b of rolling bearing 36 is fixed in portion, which is pre-assembled with shell 22.Next, will installation There is the cover 71 of rotation sensor 72 to be assembled in shell 22, by the rolling bearing 36 of inner disc side be assembled in the aperture surface of cover 71 with it is electronic Between the outer diameter face of machine rotary shaft 24.

Then, when the central plug 73 for being equipped with waveform spring 70 is fixed on cover 71, the assembling of motor part A terminates. At this point, the spring portion 70a of waveform spring 70 axially compressed deformation between the outer ring 36a and central plug 73 of rolling bearing 36, Therefore the outer ring 36a of the rolling bearing 36 of inner disc side is pressed to external disk side by the elastic restoring force of spring portion 70a.As a result, Apply the precompressed (level pressure precompressed) in axial direction to a pair of of rolling bearing 36,36 of supporting motor rotary shaft 24.Therefore, if selection Using the waveform spring 70 for having elastic restoring force appropriate, then can by the rolling bearing 36 of supporting motor rotary shaft 24, 36 running clearance is maintained, is managed in proper range, is able to suppress the runout of motor rotation axis 24.

In the case where considering the assemblability of motor part A, including waveform spring 70 is configured as in the present embodiment Disk side, in the case where the terminal stage of the assembling of motor part A applies the assembling sequence of precompressed, in confirmation motor rotation axis In terms of 24 movement preferably.The reason is that configured in the case where external disk side (left side of Fig. 1) by waveform spring 70, Waveform spring 70 is blocked by rotor 23b when assembling motor part A, it is difficult to confirm whether waveform spring 70 is configured with prescribed manner (whether being suitably applied with precompressed).

In addition, in the present embodiment, using ceramic balls as the ball 36c for constituting rolling bearing 36.With made of metal Ball compare, the lighter in weight of ceramic balls, therefore in addition to the high speed with motor rotation axis 24 can be effectively inhibited Other than the increase of the moment of friction (calorific value) of rotation and generation, rolling bearing 36 and in-wheel motor is being sought to drive dress It is also advantageous in terms of the lightweight for setting 21.In addition, by using ceramic balls, hence in motor part A, (wheel is interior electronic Machine actuating device 21) become in rolling bearing 36 used in this electrical equipment problem because of type of impairment caused by magnetic field Patience is improved.

In addition, using the retainer of resin as the retainer for constituting rolling bearing 36.Thereby, it is possible to make rolling bearing 36 and the further lightweight of in-wheel motor drive unit 21.It should be noted that being driven in in-wheel motor drive unit 21 When dynamic, as described above, motor rotation axis 24 is with 15000min^-1Degree high speed rotation, be based on this relationship, rolling bearing 36 member of formation also substantially heats up.Therefore, as the resin keeper for constituting rolling bearing 36, use is preferably selected by with resistance to The retainer that hot excellent resin resin material as main component is made, in particular, it is preferred that using with polyphenylene sulfide (PPS), the material as main component such as polyether-ether-ketone (PEEK), polyamide (PA).In the resin illustrated above, with polyamide 46 (PA46), polyamide 66 (PA66) etc. are that the polyamide (PA) of representative is cheap and have higher heat resistance, therefore Particularly preferably.

Certainly, the retainer as rolling bearing 36 also can replace resin keeper and use metal retainer (for example, retainer made of iron).

Next, being carried out according to in-wheel motor drive unit 21 of Fig. 7~Figure 13 to an embodiment of the second invention Explanation.Fig. 7 is the summary longitudinal section view of in-wheel motor drive unit 21, and Fig. 8 is the sectional elevation at the O-O of Fig. 7, and Fig. 9 is The explanatory diagram for acting on the load of curve ruler is shown, Figure 10 is the sectional elevation of rotary pump, and Figure 11 a is by motor rotation axis The amplified partial, longitudinal cross-sectional of reduction part side section, Figure 11 b are the pressing members when the P-P line of Figure 11 a is observed to view Main view, Figure 12 are the amplified longitudinal section views of motor rotation axis that will be equipped with rotor, and Figure 13 is the vertical profile of waveform spring View.Overall structure is said before the feature structure of the in-wheel motor drive unit to present embodiment is illustrated It is bright.

As shown in fig. 7, in-wheel motor drive unit 21 has: generating the motor part A of driving force；Make motor part A Rotation slow down and export reduction part B；And the vehicle for transmitting the output from reduction part B to driving wheel 14 (referring to Fig.1 7) Wheel is accommodated in shell 22 with bearing portion C, motor part A and reduction part B, and is installed on electric motor vehicle 11 as shown in figure 17 In car wheel cover 12a.In the present embodiment, shell 22 is passed through using the structure that can be divided into motor part A Yu reduction part B Bolt is fastened.In this description and in the claims, shell 22 refers to the casing part and receipts of receiving motor part A Hold this both sides of the casing part of reduction part B.

Motor part A is radial clearance motor, is had: being fixed on the stator 23a of shell 22；Configuration is stator 23a's Inside with stator 23a across the rotor 23b in gap radially and opposed position；And it is fixedly linked on rotor 23b's Inside and the motor rotation axis 24 rotated integrally with rotor 23b.

The motor rotation axis 24 of hollow structure is fitted and fixed with the aperture surface in rotor 23b and rotates integrally, and in electricity In motivation portion A, an axial side end (right side of Fig. 7) is rotatably supported by rolling bearing 36a ', passes through the axis of rolling 36b ' is held to rotatably support axial end side (left side of Fig. 7).

The axial side substantially central portion (right side of Fig. 7) of reducer input shaft 25 is rotatably freely supported on rolling bearing 37a, and revolved axial end side (left side of Fig. 7) bearing relative to reducer output shaft 28 by rolling bearing 37b Turn freely.Reducer input shaft 25 has eccentric part 25a, 25b in reduction part B.In order to cancel out each other because eccentric motion generates Centrifugal force, two eccentric parts 25a, 25b are arranged in a manner of changing 180 ° of phases.

Motor rotation axis 24 and reducer input shaft 25 pass through spline (including sawtooth.It is same as below.) be fitted into and link, The driving force of motor part A is transmitted to reduction part B.The spline fitting portion is configured to, even if the certain journey of reducer input shaft 25 The inclination of degree ground, also inhibits the influence to motor rotation axis 24.

Reduction part B has: as revolution component curve ruler 26a, 26b, be rotatably freely held in eccentric part 25a, 25b；As multiple export trades 27 of peripheral snap component, engage with the peripheral part of curve ruler 26a, 26b；Movement conversion mechanism, It transmits the spinning motion of curve ruler 26a, 26b to reducer output shaft 28；And balance weight 29, it is located at and eccentric part 25a, 25b adjacent position.

Reducer output shaft 28 has flange part 28a and axle portion 28b.In flange part 28a with reducer output shaft 28 Fixed domestic 31 hole is alternately formed on circumference centered on axis of rotation etc..In addition, axle portion 28b connects by the way that spline is chimeric It ties in the wheel hub 32 of the inner member as wheel bearing portion C, the output of reduction part B is transmitted to wheel 14.Retarder is defeated Shaft 28 is rotatably freely supported on export trade cover 60 by rolling bearing 46.

As shown in figure 8, curve ruler 26a has the multiple waves being made of trochoids system curves such as the outer trochoids of circle in peripheral part Shape, and there are the multiple through hole 30a and through hole 30b penetrated through from a side end face to another side end face.Through hole 30a is with song It has been equally spaced multiple on circumference centered on the rotation axle center of line plate 26a, and has accommodated aftermentioned domestic 31.In addition, passing through Through-hole 30b is set to the center of curve ruler 26a, and chimeric with eccentric part 25a.

Curve ruler 26a is supported to rotate freely relative to eccentric part 25a by rolling bearing 41.As shown in figure 8, rolling Dynamic bearing 41 is cylinder roller bearing, is had: it is chimeric with the outer diameter face of eccentric part 25a and outer diameter face have inner track face The inner ring 42 of 42a；It is formed directly into the outer side track face 43 of the aperture surface of the through hole 30b of curve ruler 26a；Configuration is in interior siding track Multiple cylindrical rollers 44 between road face 42a and outer side track face 43；And the retainer of cylindrical roller 44 is kept (to save sketch map Show).In addition, inner ring 42 has from the axial ends portion of inner track face 42a to radial outside flange part outstanding.

As shown in figure 8, export trade 27 is equally spaced set on the circumference centered on the axis of rotation of reducer input shaft 25 It sets.When curve ruler 26a, 26b carry out revolution motion when, the waveform of curve shape engages with export trade 27, thus make curve ruler 26a, 26b generates spinning motion.Export trade 27 is supported to rotate relative to outer pin boss body 60 by needle bearing 27a (referring to Fig. 7) Freely.Thereby, it is possible to reduce the contact resistance between curve ruler 26a, 26b.

Balance weight 29 (referring to Fig. 7) is in generally fan-shaped shape, has the through hole chimeric with reducer input shaft 25, in order to disappear Except the unbalance inertia force that generates by the rotation of curve ruler 26a, 26b is even, the position adjacent with each eccentric part 25a, 25b with Eccentric part 25a, 25b are configured with changing 180 ° of phases.

As shown in fig. 7, movement conversion mechanism includes: to be held in multiple domestic the 31 of reducer output shaft 28 and be set to song The through hole 30a of line plate 26a, 26b.Domestic 31 on the circumference centered on the axis of rotation of reducer output shaft 28 at equal intervals Reducer output shaft 28 is fixed in ground setting (referring to Fig. 8), an axial side end.In addition, in order to reduce with curve ruler 26a, The frictional resistance of 26b is provided with needle bearing in the position of curve ruler 26a, 26b abutted with the inner wall of through hole 30a 31a。

Axial end side domestic 31 is provided with stabilizer 31b.Stabilizer 31b includes the annular portion of annulus shape The 31c and cylindrical portion 31d axially extended from the aperture surface of annular portion 31c.Multiple domestic 31 axial end side is solid Due to annular portion 31c.Domestic 31 load applied from curve ruler 26a, 26b to a part are via stabilizer 31b by all It is domestic 31 bearing, therefore can reduce act on domestic 31 stress, to improve durability.

Through hole 30a setting with multiple domestic 31 corresponding positions, the internal diameter of through hole 30a is set as comparing Domestic 31 outer diameter (refers to " maximum outside diameter including needle bearing 31a ".It is same as below.) big predetermined size.

It is illustrated according to state of the Fig. 9 to the load for acting on curve ruler 26a, 26b.The axle center O of eccentric part 25a₂From The eccentric eccentric amount e of the axle center O of reducer input shaft 25.Curve ruler 26a, eccentric part 25a are installed in the periphery of eccentric part 25a Curve ruler 26a is rotatably supported, therefore, axle center O₂It also is the axle center of curve ruler 26a.The periphery of curve ruler 26a is by wave Shape curve is formed, and equally spaced has the recess portion 34 of the radially upper waveform being recessed in the circumferential.Around curve ruler 26a, It is equipped with multiple export trades 27 engaged with recess portion 34 in the circumferential centered on the O of axle center.

In Fig. 9, when eccentric part 25a rotates counterclockwise on paper together with reducer input shaft 25, partially Center portion 25a carries out the revolution motion centered on the O of axle center, therefore the recess portion 34 of curve ruler 26a is circumferentially successively supported with export trade 27 It connects.As a result, as shown by arrows, curve ruler 26a is from multiple export trades 27 by load Fi, along clockwise direction rotation.

In addition, with axle center O on curve ruler 26a₂Centered on and be equipped with multiple through hole 30a in the circumferential.With deceleration Domestic the 31 of the combination of device output shaft 28 pass through each through hole 30a, which coaxially configures with axle center O.Perforation The big predetermined size of outer diameter of the internal diameter of hole 30a than domestic 31, therefore domestic 31 will not be as the barrier of the revolution motion of curve ruler 26a Hinder, domestic 31 extract the spinning motion of curve ruler 26a and rotate reducer output shaft 28.At this point, with reducer input shaft 25 It compares, reducer output shaft 28 becomes high torque (HT) and slow speed, and as shown by the arrows in Figure 9 like that, curve ruler 26a is from multiple domestic 31 by load Fj.The resultant force F of above-mentioned multiple load Fi, Fj_sIt is applied to reducer input shaft 25.

Resultant force F_sDirection according to geometric conditions, centrifugal force such as the waveform shape of curve ruler 26a, the quantity of recess portion 34 Influence and change.Specifically, with connection rotation axle center O₂At right angle and pass through rotation axle center O with the straight line Y of axle center O₂Base Directrix X and resultant force Fs angulation_αSubstantially changed in 30 °~60 °.

Above-mentioned multiple load Fi, Fj are during reducer input shaft 25 turns around (360 °), the direction of load, size It changes, as a result, acting on the direction of the load of the resultant force Fs of reducer input shaft 25, size also changes.And And when reducer input shaft 25 turns around, the recess portion 34 of the waveform of curve ruler 26a is decelerated rotates one clockwise Spacing becomes the state of Fig. 9, repeats above situation.

As shown in fig. 7, the wheel bearing 33 of wheel bearing portion C is multiple row angular contact ball bearing, the wheel bearing 33 by be formed directly into wheel hub 32 outer diameter face inner track face 33f and be embedded in outer diameter face path stage portion inner ring 33a and form inner member, and have: outer ring 33b is fitted and fixed in the aperture surface of shell 22；As the multiple of rolling element Ball 33c, they are configured between inner track face 33f, inner ring 33a and outer ring 33b；Retainer 33d keeps adjacent The interval of ball 33c；And containment member 33e, the axial ends portion of wheel bearing 33 is sealed.

Next, being illustrated to lubricating structure.The lubricating structure provided to cool down motor part A lubricating oil and Lubricating oil is supplied to reduction part B.The lubricating structure specifically includes that lubricant passage way 24a, 25c shown in Fig. 7, oil port 24b, 25d, 25e, 25f, lubricating oil outlet 22b, lubricating oil accumulating part 22d, lubricant passage way 22e, rotary pump 51 and circulation Oil circuit 45.The hollow arrow marked in lubricating structure indicates the flow direction of lubricating oil.

The lubricant passage way 25c connecting with the lubricant passage way 24a of motor rotation axis 24 is in the inside of reducer input shaft 25 Extend along axis direction.Oil port 25d, 25e prolong from lubricant passage way 25c towards the outer diameter face of reducer input shaft 25 It stretches, oil port 25f extends in axis of rotation side upwardly toward axial end from the shaft end portion of reducer input shaft 25.

At least one position of shell 22 at the position of reduction part B is provided with the lubricating oil inside discharge reduction part B Lubricating oil outlet 22b, and be provided with and temporarily stockpile the lubricating oil accumulating part 22d of lubricating oil be discharged.

As shown in fig. 7, circulating oil path 45 includes: the axial oil circuit 45a axially extended in the inside of shell 22；With axis The radial oil circuit 45c for connecting and radially extending to the axial one end (right side of Fig. 7) of oil circuit 45a；And and axial oil The radial oil circuit 45b that axial the other end (left side of Fig. 7) of road 45a connects and radially extends.

In order to forcibly make lubrication oil circulation, in the lubricant passage way 22e and circulating oil path being connect with lubricating oil accumulating part 22d Rotary pump 51 is provided between 45.Radial oil circuit 45b by from the lubricating oil of 51 force feed of rotary pump in the axial direction oil circuit 45a supply, and Lubricating oil is supplied via radial oil circuit 45c to lubricant passage way 24a, 25c from axial oil circuit 45a.

As shown in Figure 10, rotary pump 51 is Gerotor pump, is had: being rotated using the rotation of reducer output shaft 28 Internal rotor 52；The outer rotor 53 of driven rotation is carried out with the rotation of internal rotor 52；Pump chamber 54；It is connected to lubricant passage way 22e Suction inlet 55；And the outlet 56 being connected to the radial oil circuit 45b of circulating oil path 45.By the way that rotary pump 51 is configured outside In shell 22, the enlargement whole as in-wheel motor drive unit 21 can be prevented.

Internal rotor 52 is rotated centered on rotation center c1, and on the other hand, outer rotor 53 is with rotation center c₂Centered on And it rotates.Internal rotor 52 and outer rotor 53 are respectively with different rotation center c₁、c₂Centered on and rotate, therefore pump chamber 54 Volume continuously changes.The lubricating oil flowed into as a result, from suction inlet 55 is from outlet 56 to radial oil circuit 45b force feed.

As the cooling of motor part A, as shown in fig. 7, the lubricating oil to flow back from circulating oil path 45 to lubricant passage way 24a A part rotor 23b is cooled down from oil port 24b by centrifugal force, later, lubricating oil disperse and to stator 23a It is cooled down.

As the lubrication of reduction part B, the lubricating oil of lubricant passage way 25c passes through the rotation generation with reducer input shaft 25 Centrifugal force and pressure and from oil port 25d, 25e to reduction part B flow out.It is flowed out from oil port 25d Lubricating oil is lubricated the cylinder roller bearing 41 (referring to Fig. 8) of bearing curve plate 26a, 26b, and then on one side by centrifugal force The abutment portion that curve ruler 26a, 26b abutment portion abutted with domestic 31 and curve ruler 26a, 26b are abutted with export trade 27 It is mobile to radial outside on one side etc. being lubricated.The lubricating oil flowed out from oil port 25e, 25f, which is supplied to bearing, to slow down Deep groove ball bearing 37a, 37b of device input shaft 25, and internal bearing, abutment portion.

The lubricating oil for reaching the inner wall of shell 22 is discharged from lubricating oil outlet 22b and is accumulated in lubricating oil accumulating part In 22d.Lubricating oil accumulating part 22d is provided between lubricating oil outlet 22b and rotary pump 51, so even temporarily generating not The lubricating oil can be also accumulated in lubricating oil accumulating part 22d by the lubricating oil drained by rotary pump 51.As a result, can Prevent the increase of the torque loss of reduction part B.On the other hand, even if the lubricants capacity for reaching lubricating oil outlet 22b is less, rotation Turning pump can also make the lubricating oil being accumulated in lubricating oil accumulating part 22d flow back to lubricant passage way 24a, 25c.Lubricating oil by from Mental and physical efforts and gravity and move.Thus it is preferred to which lubricating oil accumulating part 22d is positioned at the side of the lower part of in-wheel motor drive unit 21 Formula is installed on electric motor vehicle 11.

The overall structure of the in-wheel motor drive unit 21 of present embodiment as described above, it is following to its feature structure into Row explanation.

As shown in fig. 7, motor part A is fixed with stator 23a on shell 22, in the inside of stator 23a configuration with it is fixed Rotor 23b of the sub- 23a across gap radially and opposed position.Rotor 23b is fitted and fixed in motor rotation axis 24 Outside is integrally rotated with motor rotation axis 24.

An axial side end (right side of Fig. 7) of the motor rotation axis 24 in shell 22 passes through the depth as rolling bearing Ditch ball bearing 36a ' and be supported to rotate freely, and in axial end side (left side of Fig. 7) by as the axis of rolling The deep groove ball bearing 36b ' that holds and be supported to rotate freely.

It is shown in FIG. 12 motor rotation axis 24 and the amplified vertical section rotor 23b.Motor rotation axis 24 It is made of case-hardened steels such as SCM415, SCM420, implements carburizing and quenching tempering repeatedly.It is indicated at heat by crossing section line Manage hardened layer H.The surface for implementing carburizing and quenching tempering of motor rotation axis 24 becomes the high rigidity of HRC62~66.5.Separately On the one hand, the hardness of central part is HRC29~38 or so.

In the part of the major diameter outer diameter part 61 ' of motor rotation axis 24 being fitted into for rotor 23b, and the end of side is formed There is the flange part 62 for constraining rotor 23b in the axial direction.The lateral surface 62a of flange part 62 implements the processing of anti-carbon, the part it is hard Degree is HRC29~38 or so.For the inside diameter of the major diameter outer diameter part 61 ' and rotor 23b of motor rotation axis 24 cooperation and Speech, the magnitude of interference of the selected expansion for considering centrifugal force generation and thermal expansion, is formed as interference fit, shrink fit.In interference In the case where cooperation, pressed while making the major diameter outer diameter part 61 ' of motor rotation axis 24 and the inside diameter of rotor 23b contacts Enter, major diameter outer diameter part 61 ' is formed with higher surface hardness, therefore can prevent the abrasion of contact portion.

After rotor 23b is pressed into until abutting with the flange part 62 of major diameter outer diameter part 61 ', make independent clamping components 63 It is fastened and fixed with the end abutment of the other side of rotor 23b and by bolt 64.In this way, rotor 23b is installed on motor rotation Axis 24.For clamping components 63, non-magnetic material and the high material of specific gravity are selected, so as to aftermentioned for carrying out uneven adjustment Machining generate cut powder and will not be adsorbed in rotor 23b.As the material of clamping components 63, preferably austenite is stainless Steel.

Referring to Fig. 7, motor rotation axis 24 is as described above with 15000min^-1Degree high speed rotation.In order to inhibit to pacify The runout of motor rotation axis 24 equipped with rotor 23b, inner ring 36a1,36b1 and motor of deep groove ball bearing 36a ', 36b ' Cooperation between rotary shaft 24 is set as transition fit or interference fit.

The bearing mounting surface 65,66 of deep groove ball bearing 36a ', inner ring 36a1,36b1 of 36b ' and motor rotation axis 24 Matching between (referring to Fig.1 2) is combined into transition fit or interference fit, but is formed with heat treatment firmly on bearing mounting surface 65,66 Change layer, therefore inner ring 36a1,36b1 will not damage bearing mounting surface 65,66 in assembling.

On the other hand, the cooperation between outer ring 36a2,36b2 and shell 22 of deep groove ball bearing 36a ', 36b ' is set as gap Cooperation.As a result, in assembling deep groove ball bearing 36a ', 36b ' rolling element will not damage orbital plane, can be avoided the longevity of bearing Life shortens.

The central part of motor rotation axis 24 has toughness, therefore deformation when being resistant to high speed rotation.Therefore, as The in-wheel motor driving of combination low torque and the motor of high-speed rotation type and the cycloidal reducer that high reduction ratio can be obtained Device and it is preferred that.

After assembling of the rotor 23b to motor rotation axis 24, in order to inhibit the forced vibration ingredient to turn around, into The uneven adjustment of row.The lateral surface 62a of the flange part 62 of major diameter outer diameter part 61 ' and the lateral surface of clamping components 63 are that balance is repaired Face just.Its reason is, in order to reduce the cutting output for imbalance adjustment, to be preferably formed in outside diameter as much as possible, will The lateral surface 62a of flange part 62 and the lateral surface of clamping components 63 are as balance amendment face.It is however not limited to this, it can also Using by either lateral surface of the lateral surface 62a of flange part 62 and clamping components 63 as the amendment face of balance.Flange part 62 Lateral surface 62a to implement the processing of anti-carbon be soft, the machinability for being accordingly used in uneven adjustment is good, manufacturing procedure Turnaround time reduce, imbalance adjustment be relatively easy to, and can be realized cost reduction.The specific gravity of clamping components 63 compared with Greatly, therefore processing capacity is less, and the turnaround time of manufacturing procedure is reduced, and imbalance adjustment is relatively easy to, and can Cost of implementation reduces.

It, can be by coating the method for anti-carburizer in outer side 62a, making for the processing of the anti-carbon of flange part 62 The method suitably such as method for then carrying out Carburization Treatment is abutted with the fixture of lateral surface 62a face contact to implement.For seeping For carbon quenching, there is the flexibility of the small change for shape, also, be easy to distinguish the heat treatment of motor rotation axis 24 Position and the position not being heat-treated, in terms of cost favorably.

In order to inhibit because deep groove ball bearing 36a ', 36b ' outer ring 36a2,36b2 and shell 22 between with being combined into gap The runout of the motor rotation axis 24 of cooperation and generation has structure shown in Figure 11 a and Figure 11 b in the present embodiment. Figure 11 a is by the spline fitting portion of motor rotation axis 24 and reducer input shaft 25 in Fig. 7 and bearing retarder input The amplified longitudinal section view of peripheral portion of the deep groove ball bearing 36b of axis 25, Figure 11 b are the P-P lines in Figure 11 a to when view observation Pressing member main view.

1a referring to Fig.1, motor rotation axis 24 are rotatably freely supported on shell 22 by deep groove ball bearing 36b '.It is deep Matching between the inner ring 36b1 of ditch ball bearing 36b ' and the bearing mounting surface 66 of motor rotation axis 24 is combined into transition fit or mistake Be full of cooperation, between outer ring 36b2 and the bearing mounting surface 22a of shell 22 with being combined into clearance fit.It is pressed the end face of outer ring 36b2 Component 67 is pressed to press.As shown in figure 11b, pressing member 67 is hollow plectane, is provided in outside diameter and is inserted into for multiple bolts 68 Through hole 67a.The part for imposing hatching of the internal side diameter of pressing member 67 is the abutting abutted with the end face of outer ring 36b2 Portion.After deep groove ball bearing 36b ' to be assembled in the bearing mounting surface 22a of shell 22, pressing member 67 is fastened by bolt 68 In shell 22, the end face of the part pressing outer ring 36b2 of the hatching of the side of pressing member 67 is thus by deep groove ball bearing 36b ' It is fixed.

Motor rotation axis 24 links by the way that spline is chimeric with reducer input shaft 25, but the work influence of reduction part B should Spline fitting portion.The outer pin boss body 60 of the export trade 27 shown in Fig. 7 for keeping reduction part B passes through the rotation stop with elastic bearing function Mechanism (illustration omitted) is supported on shell 22 with quick condition.The reason is that absorbing the turning because of vehicle, anxious acceleration-deceleration Biggish radial load, the torque load of equal generations prevent curve ruler 26a, 26b, export trade 27 and by curve ruler 26a, 26b Eccentric swing moves the breakage for being converted to the various parts such as the movement conversion mechanism of rotary motion of reducer output shaft 28.

In the state of above-mentioned floating structure, as described above, reducer input shaft 25 has from curve ruler 26a, 26b effect Radial load, the torque load that the direction of load, size change.Therefore, it is tilted, under misaligned state there are a degree of, Motor rotation axis 24 and reducer input shaft 25 are in the transmitting torque of spline fitting portion.But as described above, deep groove ball bearing Matching between the outer ring 36b2 and shell 22 of 36b ' is combined into clearance fit, and the end face of outer ring 36b2 is pressed the pressing of component 67, because This be able to suppress because generated between motor rotation axis 24 and reducer input shaft 25 straight line registration error, spline fitting portion Situations such as playing vibration caused by tooth of engagement.Due to such working condition, component 67 will be pressed and pressed outside bearing The bearing of the end face of circle is set as the side chimeric with 25 spline of reducer input shaft of motor rotation axis 24 (reduction part side end) Deep groove ball bearing 36b ' be effective.

For pressing member 67, as the component that can obtain assemblability and pressing force appropriate, preferably plate Material.If plate, then pressing force can be easily varied by changing plate thickness, in addition it is possible to easily cope with press section Shape change.Also, plate thickness is preferably 0.5~5mm.In the case where plate thickness is 0.5mm situation below, pressing force is smaller, bearing Retentivity become smaller, so not preferably, on the other hand, plate thickness be 5mm or more in the case where, cannot achieve for take turns in it is electronic The structural requirement of machine actuating device is axial shortening, not preferably.

In addition, the Bearing inner gap of the deep groove ball bearing 36a ' of supporting motor rotary shaft 24,36b ' are motor rotations One of an important factor for runout of shaft 24.Therefore, in the present embodiment, deep groove ball bearing 36a ', 36b ' are previously applied Load (precompressed) is eliminated Bearing inner gap and is used.

The method for applying precompressed has positioning to set precompressed and level pressure precompressed.For example, the method mechanically positioned belongs to Precompressed is set in positioning, belongs to level pressure precompressed using the method for spring element.In the material of motor rotation axis 24 and the material of shell 22 In the case that matter is different, there is a possibility that changing precompressed because of thermal expansion difference in the method mechanically positioned.Therefore, It is preferred that being not easily susceptible to the level pressure precompressed of the influence of the variation of the axial displacement generated by thermal expansion difference.The level pressure of present embodiment is pre- Pressure precompressed amount preferably generally, by the motor rotation axis chimeric with deep groove ball bearing 36a ', inner ring 36a1,36b1 of 36b ' In the case that 24 diameter of axle is set as d, precompressed amount is set as to the range of 4d~10d (N).As realize level pressure precompressed mechanism, As shown in figure 13, using waveform spring 70.

Figure 13 is the longitudinal section view of waveform spring 70.The waveform spring 70 is formed and leaf spring is wound spiral, Central portion in the axial direction, which has, bends to undulatory spring portion 70a, has flat seat surface 70b at both ends.Pass through pressure It contracts the waveform spring 70 and precompressed is applied to bearing.

Referring to Fig. 7, to the method for the level pressure precompressed in the application axial direction of a pair of of rolling bearing 36,36 for using waveform spring 70 It is illustrated.Stator 23a is mounted on the electricity for the state that back cover 71 is removed by the summary of the assembling as motor part A In the state of the inner circumferential of the shell 22 of motivation portion A, the zanjon of motor rotation axis 24 and supporting motor rotary shaft 24 is assembled Ball bearing 36a ', 36b '.It should be noted that the shell 22 of reduction part B divides from the shell 22 of motor part A in the assembling From.Firstly, the deep groove ball bearing 36b of retarder side to be assembled in the bearing mounting surface 22a (1a referring to Fig.1) of shell 22, pass through Pressing member 67 is anchored on shell 22 to press the end face of the outer ring 36b2 of deep groove ball bearing 36b ' by bolt 68.Next, By the motor rotation axis 24 for being equipped with the rotor 72a of rotor 23b and rotation sensor 72 be inserted into the axial other side (Fig. 7's Left side), it is pressed into the internal diameter of the inner ring 36b1 of deep groove ball bearing 36b '.

Later, by the chimeric bearing mounting surface for being inserted into the back cover 71 for being equipped with rotation sensor 72 of motor rotation axis 24 In 71a, back cover 71 is assembled in axial side (right side of Fig. 7) end of shell 22.Then, by deep groove ball bearing 36a ' insertion Between the bearing mounting surface 71a of back cover 71 and the bearing mounting surface 65 of motor rotation axis 24.At this point, motor rotation axis 24 Matching between bearing mounting surface 65 and the inner ring 36a1 of deep groove ball bearing 36a ' is combined into transition fit or interference fit, therefore is formed Indentation.

Later, the central plug 73 for being equipped with waveform spring 70 is fitted into and is inserted in back cover 71 and fixes.Compressed waveform spring 70, the end face of the outer ring 36a1 of deep groove ball bearing 36a ' is pressed in the axial direction the other side (left side of Fig. 7) by elastic force.Its result To be applied with precompressed (level pressure precompressed) to a pair of of deep groove ball bearing 36a ', 36b '.Thereby, it is possible to eliminate supporting motor rotation The Bearing inner gap of the deep groove ball bearing 36a ' of axis 24,36b ', are able to suppress the runout of motor rotation axis 24.In addition, by Apply level pressure precompressed in passing through waveform spring 70, therefore is able to suppress the thermal expansion difference because of shell 22, motor rotation axis 24 etc. The variation of the precompressed of generation.

In the case where considering the assemblability of motor, as in the present embodiment by pre-compressed spring (waveform spring 70) Configuration is on axial side (right side of Fig. 7), in the case where the terminal stage of assembling applies the assembling sequence of precompressed, in confirmation electricity In terms of the movement of motivation rotary shaft 24 preferably.On the contrary, in the axis by pre-compressed spring configuration in axial another side (left side of Fig. 7) In the case where holding 36b ', in assembling, pre-compressed spring is blocked by rotor 23b, it is difficult to it is confirmed whether normally to be applied with precompressed, and Not preferably.

The variation of pressing member is shown in Figure 14.The base portion 74 of the pressing member 67 ' including hollow plectane and from the base The multiple protruding portion 75 prominent to internal diameter side of portion 74.The part for imposing hatching of the internal side diameter of protruding portion 75 is and outer ring 36b2 End face abut abutting part.In the pressing member 67 ' of this variation, multiple protruding portion 75 applies pressing force respectively, because right Trackability in the end face of outer ring 36b2 is excellent, applies stable pressing force.

The in-wheel motor drive unit 21 of present embodiment described above can with can be used low torque and high speed revolve The motor of transition correspondingly seeks the inhibition of the forced vibration ingredient to turn around, and small-sized, light weight, silence is excellent, and Improve durability.

Referring to Fig.1, the embodiment and the second invention of Fig. 2, Fig. 7 and Fig. 8 to the first invention with the above structure The whole working principle of in-wheel motor drive unit 21 of embodiment be illustrated.

In motor part A, such as by because supplying alternating current due to the electromagnetic force that generates to the coil of stator 23a, from And the rotor 23b rotation being made of permanent magnet or magnetic substance.It is accompanied by this, when the retarder linked with motor rotation axis 24 When input shaft 25 rotates, curve ruler 26a, 26b carry out revolution motion centered on the axis of rotation of reducer input shaft 25.This When, export trade 27 engages with the waveform of the curve shape for the peripheral part for being set to curve ruler 26a, 26b, make curve ruler 26a, 26b to The direction opposite with the rotation of reducer input shaft 25 carries out rotation rotation.

Across domestic 31 inner wall with the spinning motion of curve ruler 26a, 26b and with through hole 30a of through hole 30a It abuts.As a result, the revolution motion of curve ruler 26a, 26b not to it is domestic 31 transmitting, only the spinning motion of curve ruler 26a, 26b via Reducer output shaft 28 is transmitted to wheel bearing portion C.At this point, the rotation of reducer input shaft 25 is decelerated by reduction part B And to reducer output shaft 28 transmit, therefore even if using low torque, high-speed rotation type motor part A in the case where, Torque needed for capable of being transmitted to driving wheel (rear-wheel) 14.

The quantity of export trade 27 is being set as Z_A, the quantity for the waveform for being set to the peripheral part of curve ruler 26a, 26b is set as Z_B When, the reduction ratio of the reduction part B of above structure passes through (Z_A-Z_B)/Z_BTo calculate.In Fig. 2 and embodiment shown in Fig. 8, Z_A=12, Z_B=11, therefore the very big reduction ratio that reduction ratio is 1/11 can be obtained.

In this way, can be obtained by using the reduction part B that can obtain big retarding ratio in the case where not using multilevel structure To the in-wheel motor drive unit 21 of small-sized and high reduction ratio.In addition, being provided with the axis of rolling in export trade 27 and domestic 31 (needle bearing) 27a, 61,31a are held, so that the frictional resistance between curve ruler 26a, 26b and export trade 27 and domestic 31 reduces, Therefore the transmission efficiency of reduction part B improves.

By above structure, light weight, small-sized and silence (NVH characteristic) and excellent in te pins of durability can be realized In-wheel motor drive unit 21.Therefore, if the in-wheel motor device 21 of present embodiment is equipped on electric motor vehicle 11, Then it is able to suppress nonspring carried mass.As a result, can be realized the electric motor vehicle of riding stability and NVH excellent 11。

More than, to the in-wheel motor drive unit for the embodiments of the present invention that first invention and the second invention are constituted 21 are illustrated, but in-wheel motor drive unit 21 can implement various changes without departing from the spirit and scope of the invention More.

For example, in the embodiment described above, show oil port 24b being set to motor rotation axis 24, oil port 25e is set near rolling bearing 37a, by oil port 25d be set to eccentric part 25a, Oil port 25f is set to the example of the shaft end of reducer input shaft 25 by 25b, but not limited to this, electricity can be set Any position of motivation rotary shaft 24, reducer input shaft 25.

More than in addition, the example of Gerotor pump is shown as rotary pump 51, but not limited to this, it can be slowed down using utilizing The so-called rotary-type pump that the rotation of device output shaft 28 is driven.In addition it is also possible to omit rotary pump 51, only pass through centrifugal force And make lubrication oil circulation.

In addition, though the example that curve ruler 26a, 26b of reduction part B are changed into 180 ° of phases and are arranged two is shown, But the number of the curve ruler can arbitrarily be set, for example, in the case where three curve rulers are arranged, thus it is possible to vary 120 ° of phases And it is arranged.

More than in addition, by being fixed on domestic the 31 of reducer output shaft 28 and being set to passing through for curve ruler 26a, 26b Through-hole 30a constitutes movement conversion mechanism, but movement conversion mechanism can be any to transmit the rotation steering wheel hub 32 of reduction part B Structure.For example, it is also possible to constitute movement interpreter with the hole for being formed in reducer output shaft by being fixed on the domestic of curve ruler Structure.

The explanation of the movement of embodiment is conceived to the rotation of each component and carries out, the power actually including torque It is transmitted from motor part A to rear-wheel 14.Therefore, the power being decelerated as described above becomes the power for being converted to high torque (HT).

In addition it is shown that supplied electric power and drive motor portion to motor part A, by power from motor part A to The case where rear-wheel 14 transmits, but can also in contrast, in vehicle deceleration or descending lead to the power from 14 side of rear-wheel It crosses reduction part B to be converted to the rotation of high speed rotation low torque and transmit to motor part A, be generated electricity by motor part A.And And the electric power issued here can store in battery, have later as drive motor portion A or vehicle its The movement electric power of his electrical equipment etc. and use.

Alternatively, it is also possible to brake additional in in-wheel motor drive unit 21.For example, can be Fig. 1's and Fig. 7 In structure, parking brake can be used, is formed on the inside of the vehicle width direction of rotor 23b empty axially elongating shell 22 Between, if having the rotating member integrally rotated with rotor 23b in the space configuration, can not rotating in the housing 22 and can be along axis To mobile piston and make the working cylinder of the piston action, then when vehicle stops, by piston and rotating member by rotor 23b locking.In addition, brake can use disk brake, the disk brake by being set to the working cylinder of 22 side of shell, It is clamped in a part flange formed of above-mentioned rotating member and the friction plate being arranged in 22 side of shell, drum-type system can also be used Dynamic device, which is formed with drum at a part of place of the rotating member, and brake-shoe is fixed on 22 side of shell, leads to It crosses friction engaging and locks rotating member from engagement.

More than in addition, applies motor part A and use the structure of radial clearance motor, but can also be suitably applied to Motor part A uses the case where axial gap electric motor for keeping stator opposed with gap of the rotor in axial direction.

In addition, in-wheel motor drive unit of the invention can not only be applied to for rear-wheel 14 to be set as the rear-wheel of driving wheel The electric motor vehicle 11 for driving type, can also apply to the electronic motor-driven of the front-wheel drive type that front-wheel 13 is set as to driving wheel Vehicle, front-wheel 13 and rear-wheel 14 are set as driving wheel four-wheel drive type electric motor vehicle.It should be noted that in this theory In bright book, " electric motor vehicle " includes the concept that whole motor vehicles of driving force are obtained by electric power, such as hybrid electric vehicle Deng.

The present invention is not by above-mentioned any restriction of embodiment, without mentioning in the range for not departing from purport of the invention It is interior, additionally it is possible to implement in various ways, the scope of the present invention is shown by the range of entitlement requests, and including with entitlement requests Whole changes in range equivalent meaning and range.

Description of symbols:

11 electric motor vehicles, 12 chassis, 12a car wheel cover, 12b draft hitch, 13 front-wheels, 14 rear-wheels, 21 in-wheel motors Driving device, 22 shells, 22a bearing mounting surface, 22b lubricating oil outlet, 22d lubricating oil accumulating part, 22e lubricant passage way, 23a Stator, 23b rotor, 24 motor rotation axis, 25 reducer input shafts, 25a eccentric part, 25b eccentric part, 25c lubricant passage way, 25d oil port, 25e oil port, 26a curve ruler, 26b curve ruler, 27 export trades, 27a needle bearing, 28 slow down Device output shaft, 29 balance weights, 30b through hole, 31 is domestic, 31a needle bearing, 31b stabilizer, 31c annular portion, 31d cylindrical portion, 32 wheel hubs, 33 wheel bearings, 33a inner ring, the outer ring 33b, 33c ball, 33d retainer, 33e containment member, 33f inner track Face, the outer ring 36a, 36a ' rolling bearing, 36b inner ring, 36b ' rolling bearing, 36c ball (rolling element), 37a rolling bearing, 37b Rolling bearing, 41 rolling bearings, 42 inner rings, 43 outer side track faces, 44 cylindrical rollers, 45 circulating oil paths, 45a axial direction oil circuit, 45b Radial oil circuit, 45c radial direction oil circuit, 46 rolling bearings, 51 rotary pumps, 52 internal rotors, 53 outer rotors, 54 pump chambers, 55 suction inlets, 56 Outlet, 60 export trade covers, 61 rolling bearings, 61 ' major diameter outer diameter parts, 62 flange parts, 62a lateral surface, 63 clamping components, 65 bearings Mounting surface, 66 bearing mounting surfaces, 67 pressing members, 67 ' pressing members, 68 bolts, 70 waveform springs, A motor part, B slow down Portion, C wheel bearing portion, H are heat-treated hardened layer, the inner radial gap before δ assembling.

Claims

1. a kind of in-wheel motor drive unit has and keeps motor part, reduction part and the shell in wheel bearing portion,

The motor part includes

It is fixed on the stator of the shell；

The motor rotation axis of the shell is rotatably freely supported on via rolling bearing；And

The rotor being installed on the motor rotation axis,

The reduction part includes

The reducer input shaft rotated by the motor rotation axis by driving；And

The reducer output shaft that the rotation of the reducer input shaft after deceleration is transmitted to the wheel bearing portion,

The in-wheel motor drive unit is characterized in that,

Inner radial gap before the assembling of the rolling bearing is 8 μm~25 μm,

The level pressure precompressed being applied on the rolling bearing in axial direction.

2. in-wheel motor drive unit according to claim 1, which is characterized in that

Level pressure precompressed in the axial direction is applied by capableing of the elastic component of flexible deformation in the axial direction.

3. in-wheel motor drive unit according to claim 1 or 2, which is characterized in that

The rolling element for constituting the rolling bearing is ceramic balls.

4. in-wheel motor drive unit according to claim 1 or 2, which is characterized in that

The retainer for constituting the rolling bearing is made of resin.

5. in-wheel motor drive unit according to claim 1 or 2, which is characterized in that

The in-wheel motor drive unit also has the lubricating structure to motor part supply lubricating oil.

6. in-wheel motor drive unit according to claim 1 or 2, which is characterized in that

The reduction part has:

The reducer input shaft；

It is rotatably freely held in the revolution component of the eccentric part of the reducer input shaft, the revolution component is with the deceleration The rotation of device input shaft and revolution motion is carried out centered on the axis of rotation of the reducer input shaft；

The peripheral snap component for engaging with the peripheral part of the revolution component and the revolution component being made to generate spinning motion；And

The spinning motion of the revolution component is converted into the fortune of the rotation centered on the axis of rotation of the reducer input shaft Movement conversion mechanism that is dynamic and being transmitted to the reducer output shaft.

7. a kind of in-wheel motor drive unit has motor part, reduction part, wheel bearing portion and shell,

The motor part includes:

It is fixed on the stator of the shell；

The motor rotation axis of the shell is rotatably freely supported on via multiple rolling bearings；And

The rotor being installed on the motor rotation axis,

The motor rotation axis of the motor part drives the reducer input shaft of the reduction part to rotate, and makes the retarder The rotation of input shaft is slowed down and is transmitted to reducer output shaft, and the wheel bearing portion and the reducer output shaft link,

The in-wheel motor drive unit is characterized in that,

The motor rotation axis is rotatably freely supported on the shell via multiple rolling bearings, the motor rotation Matching between axis and the rolling bearing of the bearing motor rotation axis is combined into transition fit or interference fit, also,

Matching between the rolling bearing and the shell is combined into clearance fit,

8. in-wheel motor drive unit according to claim 7, which is characterized in that

The motor rotation axis via a pair of of rolling bearing and by double base, fixed by making by either described rolling bearing It abuts and is fixed with the end face of bearing outer ring in the side of pressing member of the shell.

9. in-wheel motor drive unit according to claim 8, which is characterized in that

The rolling bearing fixed by the pressing member is the bearing for supporting the reduction part side end of the motor rotation axis.

10. in-wheel motor drive unit according to claim 8 or claim 9, which is characterized in that

The pressing member is hollow plectane.

11. in-wheel motor drive unit according to claim 8 or claim 9, which is characterized in that

The pressing member includes the base portion and the multiple abutting parts prominent to internal diameter side from the base portion of hollow plectane.